Tires are commonly manufactured from multiple layers and components that are placed sequentially onto a cylindrical drum. In some known techniques, a layer of air impermeable rubber is laid onto a forming surface of a drum, and one or more carcass plies are placed thereon. The terms “carcass ply,” “carcass,” “reinforcement ply” or “body ply” may each refer to a ply that extends between and from the bead portions on opposing sides of the tire, through the opposing sidewall portions, and across the crown portion of the tire. The body ply may include ferrous reinforcements.
A pair of circular beads is placed on opposing drum sides and may include bead wires and bead fillers. After the plies are turned up and the beads moved towards each other to create a toroidal shape, a sidewall protective rubber and a tread portion are added.
It is well-known to adapt tire manufacturing techniques for the construction of self-supporting tire systems that include reinforced sidewalls (as used herein, “self-supporting tire system” and “self-supporting tire” may be used interchangeably). Such self-supporting tire systems, in supporting a vehicle upon loss of air pressure, permit continued vehicle operation up to a predetermined speed and distance (typically specified by the tire manufacturer). Self-supporting tire systems help drivers maintain control in the absence or near-absence of air pressure and work reliably with a variety of synergistic technologies, including but not limited to tire pressure monitoring systems (TPMS).
There are challenges associated with the manufacture of self-supporting tires, including those having reinforcements in the sidewalls. A forming drum having a generally cylindrical shape and a flat profile along the axial direction may also include recesses for accepting features such as circular beads. When reinforcements are presented onto the forming drum before a carcass ply or reinforcing ply is laid thereonto, the reinforcements create a profile that is no longer flat along the axial direction of the drum. Presentation of a carcass ply onto this uneven profile can result in undesirable creases or wrinkles, notably when attempting to press the carcass ply towards the forming drum to make contact with an air impermeable layer disposed thereon. Consequently, these creases may incur deradialization, that is, an undesirable orientation and positioning of cords and/or other reinforcing elements present in the reinforcing ply. Additionally, variance may occur in the overlap of the joint of the ply ends. Solutions to such challenges are provided by co-owned and co-pending international application number PCT/US2012/043456 for a METHOD FOR ADHERING AN INNERLINER TO A CARCASS PLY OF A TIRE, filed 21 Jun. 2012, the entire disclosure of which is incorporated by reference herein.
Complementary solutions for effective posing and assembling processes have been developed that accurately position each component of a self-supporting tire system relative to the reinforcements.